Slope of Line/Perpendicular to that Line

1) Click on the left mouse button to select line a. The cursor should change from an arrow to a hand. Move line a. What happens to m, the slope of line a?

2) Now, do the same thing for line b. What happens to m1, the slope of line b?
3) What is the slope of line a? What is the slope of line b, perpendicular to line a? How do you think that they are related?

4) Multiply the slope of line a times the slope of line b. What is the result?

5) Change the slope of line a, by changing the coefficient of x (now 2) to 4, and then to five. To do this, delete the 2 for free object line a, found at the right of this page, and replace it, first with 4, and later, with 5.

6) Repeat steps 1-4 for the new versions of line A, with slopes of 4, and then with 5.

7) What do you notice? What can you conclude? Explain your answer.

Rhonda Renker, Created with GeoGebra